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TitleKimberlites from Source to Surface: Insights from Experiments
AuthorFoley, S F; Yaxley, G M; Kjarsgaard, B AORCID logo
SourceElements: An International Magazine of Mineralogy, Geochemistry, and Petrology vol. 15, 6, 2019 p. 393-398,
Alt SeriesNatural Resources Canada, Contribution Series 20200185
PublisherMineralogical Soc Amer
Mediapaper; on-line; digital
File formatpdf
Subjectsigneous and metamorphic petrology; Nature and Environment; Science and Technology; kimberlites; pressure; petrogenesis; carbon dioxide; magmas; Experiments
Illustrationsplots; phase diagrams; models
Released2019 12 01
AbstractHigh-pressure experiments are unconvincing in explaining kimberlites as direct melts of carbonated peridotite because the lippronriate minerals do not coexist stably at the kimberlite linuiclus High-pressure melts of peridotite with CO2 and H2O have compositions similar to kimberlites only at pressures where conditions are insufficiently oxidizing to stabilize CO2: they do not replicate the high K2O/Na2O of kimberlites. Kimberlite melts may begin their ascent at approximate to 300 km depth in reduced conditions as melts rich in MgO and SiO2 and poor in Na2O. These melts interact with modified, oxidized zones at the base of cratons where they gain CO2, CaO, H2O, and K2O and lose SiO2. Decreasing CO2 solubility at low pressures facilitates the incorporation of xenocrystic olivine, resulting in kimberlites' characteristically high MgO/CaO.

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